JP2896054B2 - Drum cartridge type image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum cartridge type image forming apparatus which is applied to a copying machine, a facsimile, a printer, a multifunction machine thereof, etc. More particularly, the present invention relates to an image forming apparatus which is advantageous in reducing weight and cost.

[0002]

2. Description of the Related Art In an image forming apparatus applied to a copying machine, a facsimile, a printer, and a multifunction peripheral thereof, a drum cartridge having an image carrier such as a photosensitive drum is made detachable for convenience of manufacture and maintenance. There are things that are.

[0003] The drum cartridge is designed to slide in and out of the axial direction of the image carrier, and rails are installed so as to bridge the main frame of the apparatus main body in order to guide the slide of the drum cartridge. Have been.

In this case, the rail is configured to guide the cartridge so as to prevent the slid cartridge from entering a space outside a predetermined range. Since it is not configured to accurately position, in order to position the cartridge body at a predetermined position in the apparatus body, a plate-shaped or block-shaped positioning means,
Pressing the cartridge body against its positioning means,
A shaft or a spring having a screw for pulling is provided, and a molded portion having a receiving seat, an insertion hole or the like corresponding to the positioning means, the shaft or the spring is formed in the cartridge.

When the drum cartridge is to be mounted on the apparatus main body, the cartridge body is put on the rail and then pushed into the apparatus main body to a predetermined position, and the shaft is further tightened to bring the cartridge into contact with the positioning means. By pushing the cartridge deeper than the positioning means against the spring and releasing it, the cartridge is brought into contact with the positioning means by the pressure of the spring. Here, when a shaft is used for positioning the cartridge, for example, a positioning shaft that determines the position of the image carrier of the drum cartridge or a detent that prevents the cartridge body from rotating around the axis of the image carrier. In many cases, a plurality of shafts are required, such as a shaft for use.

By the way, in a drum cartridge,
When positioning the cartridge main body, it is necessary to accurately position the relative position between the cartridge main body and the image carrier supported by the cartridge main body.
A mechanism similar to that for positioning the cartridge in the apparatus main body is required for the cartridge. In particular, when the case of the cartridge is formed of a synthetic resin, it is highly necessary to provide such a mechanism for positioning the drum.

[0007]

As described above, in order to make the drum cartridge detachable, the apparatus main body is provided with rails, positioning means, shafts, springs, and the like. Since it is necessary to form corresponding seats and insertion holes in the cartridge, there is a problem that the number of parts is increased, the cartridge is increased in size, and the apparatus main body storing the cartridge is further increased in size.

In particular, when a mechanism for positioning the relative position between the cartridge body and the image carrier is provided in the drum cartridge, the number of parts of the cartridge increases, the drum cartridge becomes larger, and the apparatus body further increases. There is a problem that it becomes larger. In addition, there is a problem that such an increase in the size of the apparatus main body or the drum cartridge inevitably leads to an increase in weight and cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and allows easy attachment and detachment of a cartridge.
It is an object of the present invention to provide an image forming apparatus that is advantageous in reducing the size, weight, and cost.

[0010]

According to the present invention, there is provided an apparatus comprising:
In order to achieve the above object, in an image forming apparatus in which a drum cartridge having a cartridge main body and an image carrier rotatably supported via a shaft to the cartridge main body is attached and detached, the following measures are taken. ing.

That is, the shaft of the drum cartridge and the image carrier are supported at one end of the cartridge body so as to be slidable in parallel with the axial direction of the image carrier.
A spring for biasing the shaft to one side in the sliding direction is provided, and a large-diameter portion of the shaft is rotatably connected to a U-groove through which grooves formed at both ends of the shaft pass and a deep end of the U-groove. A cartridge supporting portion having a hole to be fitted is provided in the apparatus main body, and the cartridge main body is positioned in the sliding direction against the spring with respect to the positioning member and the cartridge supporting portion at the time of loading over the apparatus main body and the drum cartridge. The main body positioning means for displacing is provided.

[0012]

In the present invention, since the cartridge is attached and detached in the radial direction of the image carrier or in a direction parallel to the image carrier, rails required for attaching / detaching the cartridge become unnecessary, and the number of parts can be reduced. Also, just push the groove of the shaft together with the cartridge body to the cartridge support part,
As will be described later, the cartridge body, the shaft and the image carrier can be positioned by the spring, the body positioning means, and the cartridge supporting portion, and the drum cartridge can be easily detached from the apparatus body by performing the reverse operation. Can be.

Further, when the cartridge is loaded, the main body positioning means displaces the cartridge main body against the positioning member and the cartridge support portion in a sliding direction against a spring to a predetermined position, and the cartridge main body is received by the positioning means. The cartridge is positioned by pressing the cartridge with a spring.

Therefore, the cartridge can be easily positioned at a predetermined position only by performing a simple operation of inserting the cartridge in the radial direction of the image carrier or in a direction parallel thereto. A positioning means for receiving the cartridge in the axial direction of the image carrier is not required, and a corresponding cartridge seat, insertion hole, and the like are not required.

In particular, when the present invention is applied to an image forming apparatus using a cartridge having a drum, and the positioning member is constituted by a shaft of the drum, the cartridge supporting portion is supported only by the cartridge supporting portion. The position of the drum with respect to can be accurately positioned.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

An image forming apparatus according to one embodiment of the present invention shown in the schematic view of FIG. 1 is provided with a drum cartridge 1 which is attached to and detached from the image forming apparatus. The drum cartridge 1 is a perspective view of FIG. As shown in each plan view of FIG. 7, a cartridge body 2 made of synthetic resin, an image carrier 3 composed of a photosensitive drum, and this image carrier 3 are rotatable around one side of the cartridge body 2. And a shaft 4 to be supported.

The shaft 4 is supported by the cartridge body 2 so as to be able to advance and retreat in the axial direction of the image carrier 3 and the shaft 4, and has grooves 5 and 6 formed at both ends thereof over the entire circumference. A pair of cartridge support portions 21 and 22 are provided on the apparatus main body side corresponding to the grooves 5 and 6.

Each of the cartridge supporting portions 21 and 22 has a U-shaped groove having a width substantially equal to the diameter of the portion where the grooves 5 and 6 of the shaft 4 are formed, and formed so that the grooves 5.6 of the shaft 4 can pass therethrough. 7.8 are formed. In addition, a hole 9 is formed at the deep end of each of the U-shaped grooves 7 and 8 so that the large-diameter portion of the shaft 4 can enter and fix its position.

A stopper ring 10 is externally fitted to one end of the shaft 4, and a spring 11 fixed to the stopper ring 10 is inserted between the stopper ring 10 and the cartridge body 2. As a result, the shaft 4 is biased toward one side (the right side in FIGS. 2 to 7) of the movable range of the spring 11 in the thrust direction, that is, the axial direction of the shaft 4.

A stopper ring 13 is provided at the opposite end of the shaft 4 to prevent the cartridge body 2 from coming off the shaft 4 as shown in the plan view of FIG.
And a knob 23 for sliding the image carrier 3 is provided at the opposite end of the shaft 4.

This apparatus is further provided with main body positioning means 24 extending over the main body of the apparatus and the drum cartridge 1. The main body positioning means 24 includes a shaft 4 serving as a positioning member and a cartridge main body 2 when the drum cartridge 1 is loaded. It is only necessary that the cartridge supporting portions 21 and 22 be displaced in the sliding direction to a predetermined position against the spring 11.

For example, in this embodiment, the main body positioning means 24 is connected to the left end of the cartridge main body 2 in FIGS. 2 to 6, and is received by the front end of the cartridge support 21 on the end side. A wedge-shaped cam 12,
The cartridge support portion 21 receives the cam.

When mounting the drum cartridge 1 in the apparatus main body, first, as shown in FIG. 3, each groove 5.6 of the shaft 4 is
, And as shown in FIG.
The groove 6 is inserted into the U-groove 8 and the groove 6 is inserted into the U-groove 8 (other than the grooves 5.6 of the shaft 4 at this time). 7.8
Into the hole 9 in the back.

As a result, as shown in FIGS. 5 and 6,
The cam 12 received by the cartridge support portion 21 is pushed rightward in the drawing, and the cartridge body 2 is pushed by the projections 12 provided on the body frame and the cartridge body 2.
Is pushed downward while sliding to the right, and the relative position of the cartridge body 2 to the apparatus body is determined.

At this time, the grooves 5 and 6 of the shaft 4
Since the U-grooves 7 and 8 are fitted, the spring 11 is moved by the amount that the cartridge body 2 slides in the thrust direction.
Is compressed.

When the shaft 4 is pushed into the hole 9 at the back of the U-grooves 7, 8, the shaft 4 slides by the spring 11, and the large diameter portion of the shaft 4 is inserted into the hole 9 as shown in FIG. Is inserted. Here, since the diameter of the large diameter portion of the shaft 4 is larger than that of the U grooves 7 and 8, the shaft 4 is
-The position of the shaft 4 is fixed at a predetermined position without falling off to the 8 side. Further, at this time, the position of the shaft 4 with respect to the cartridge body 2 in the axial direction is set to a position where the shaft 4 is received by the cartridge body 2 by the retaining rings 13 and 10.

In short, according to this embodiment, the grooves 5 and 6 of the shaft 4 are aligned with the U grooves 7 and
8, the cartridge body 2 and the image carrier 3 can be positioned at predetermined positions by a one-touch operation of pushing the shaft 4 into the U grooves 7.8.

When the drum cartridge 1 is to be removed from the apparatus main body, the knob 23 provided on the shaft 4 biased by the spring 11 is moved in the thrust direction (left side in the figure), and the grooves 5 and 6 are formed in the holes 9. The drum cartridge 1 can be easily removed by pulling it out of the U-grooves 7 and 8 in accordance with.

In FIG. 1, reference numeral 14 denotes a developing device;
Is a paper feed roller, 16 is a transport rail, 17 is a paper feed cassette, 18 is a paper discharge tray, 19 is an optical unit, and 20 is a writing head.

[0031]

As described above, according to the present invention, the cartridge is easily and accurately positioned in the apparatus main body by one-touch operation of aligning the positioning member with the cartridge supporting portion supporting the positioning member and pushing the cartridge into the apparatus main body. Can be attached. Further, the cartridge mounted on the apparatus main body can be easily detached from the apparatus main body by slightly displacing the shaft in the sliding direction and pulling out the cartridge main body. As a result, the operation of attaching and detaching the cartridge is simplified, so that the operability is significantly improved.

In addition, a single set of positioning mechanisms may be provided instead of the rails for guiding the mounting and dismounting of the cartridges and the plurality of positioning mechanisms for positioning the cartridges. The small,
Since the cartridge can be made lightweight and low-priced, and it is not necessary to provide parts and moldings corresponding to these rails and the positioning mechanism in the cartridge, the cartridge can be made small, lightweight and low-priced, and the cartridge can be made compact. The apparatus main body to be stored can be made smaller, lighter, and less expensive.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of one embodiment of the present invention.

FIG. 3 is a plan view in which a part of a main part of one embodiment of the present invention is cut away.

FIG. 4 is a plan view of a main part immediately before mounting a drum cartridge according to an embodiment of the present invention.

FIG. 5 is a plan view of a main part of the embodiment of the present invention at the start of mounting the drum cartridge.

FIG. 6 is a plan view of a main part at the end of a drum cartridge mounting operation according to one embodiment of the present invention.

FIG. 7 is a plan view of a main part when the mounting of the drum cartridge is completed according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum cartridge 2 Cartridge main body 3 Image carrier 4 Shaft 4, 6 groove 7, 8 U groove 9 Hole 11 Spring 21, 22 Cartridge support 24 Main body positioning means

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Claims (1)

(57) [Claims] 1. A drum cartridge type image forming apparatus in which a drum cartridge having a cartridge main body and an image carrier rotatably supported on the cartridge main body via a shaft is attached to and detached from the apparatus main body. The shaft and the image carrier are supported at one end of the cartridge body so as to be slidable in parallel with the axial direction of the image carrier, and springs for urging the shaft to one side in the sliding direction are provided. A cartridge support portion having a U-shaped groove through which the groove formed in the groove passes and a hole continuously rotatable inside the large-diameter portion of the shaft at the inner end of the U-shaped groove; When the cartridge body is loaded, the cartridge body slides against the positioning member and the cartridge support portion against the spring. Drum cartridge type image forming apparatus characterized by a body positioning means for displacing in a direction to a predetermined position are provided.